Fire-control apparatus for naval guns



Aug. 14, 1923.

J. B. HENDERSON FIRE CONTROL APPARATUS FOR NAVAL GUNS Original Filed y26 1919 3 Sheets-Sheet I11 I III/II I I 111 11/11 LL]! I 111 11/11IVI/E/V To)? Aug. 14, 1923.

J. B. HENDERSON FIRE CONTROL APPARATUS FOR NAVAL GUNS Original FiledJuly 26. 1919 a Sheets-Sheet 2 s IM INVEN OR Aug. 14, 1923.

Original Filed July 26 1919 :5 Sheets-Sheet 5 /NVENTOR j fihouM 14mmPatented Aug. 14, 1923.

UNITED STATES PATENT creme.

JAKE BLAOKLOCK HENDERSON, OF LEE, ENGLAND.

, FIRE-CONTROL APPARATUS EOE NAVAL GUNS.

Application filed July 26,1919, Serial Io. 313,588. Renewed December 19,1922.

T 0 all whom it may concern Be it known that I. James BmcxnocxHnxosasox, a subject of the King of Great Britain, residing at 2Cambridge Road, Lee, in the county of Kent, England, have inventedcertain new and useful Improvements in and Relating to Fire-ControlApparatus for Naval Guns (for which I have tion to the horizontal plane.and optical means of controllin the position of the electrical contactsreliitively to the horizontal plane. I provide also similar contacts andsimilar control relative to the azimuthal bearing of the target inrelation to the shi To carry out mv invention I mount a ho y havingconsiderable inertia. on gimbals on a pedestal on the deck of the ship.This body is mounted preferably in neutral equilibrium on the gimbalsand in order to get the equivalent of very large inertia in smallcompass. I preferably employ a gyroscope. In the following description Ishall therefore refer to the gyroscope as the body supported in neutralequilbrium on gimbals. The gimbal axes are preferably horizontal andvertical and the rotor axis, in its normal position is perpendicular toboth. The gyroscope is enclosed in a box or casing and in order todistinguish it from the rotor casing or stator of the electric motordriving the rotor, I shall refer to the box as the outer casing and tothe other as the rotor casing. The outer casing i mounted on thepedestal and is provided with a hand training gear relatively to thepedestal. The gimbal ring is suspended say ona horizontal trunnion axison the outer casing and the rotor casing is suspended on a verticaltrunnion axis in the glmbal rin In the accompanying rawings whichillustrate mv invention Figs. 1 and 2 show respectively an elevation anda plan of one arrangement of the parts of the director sight.

Figs. 3, 4 and 5 show a side elevation, a

plan and a front elevation of an alternative arrangement which embodiesa method of optical compensation for the tilting of the gyro axis.

Fig. 6 shows a plan of an alternative arrangement of fixing thereflectors.

Figs. 7, 8, 9 and 10 show respectively a side elevation. a backelevation with the re removed, a sectional plan and a front e evation ofthe telescope of an arran ment which permits the observer to face t etarget amLwhich has optical compensation for thetilting of the gyroaxis.

Fig. 11 shows a diagram of connections. Figs. 12, 13, 14, 15 and 16 showvarious arrangements of optical systems which I may employ.

The gyro-rotor casing 1 issus nded on. a vertica trunnion axis 2 in thegimbal ring 3. which is suspended on the horizontal trunnion axis 4 inthe outer casing 5 of the instrument. I preferably arrange the gyro tobe in neutral equilibrium on the trunnion axis 2 but may give a smallavitational stability to the combination 0 gyro 1 and gimbal ring 3about the trunnion axis 4.

The outer casing 5 may be supported on any suitable mounting on thestandard director sight but for purposes of illustration it is shownmounted on a vertical axis on I the pedestal 6 with a worm T gearing ina worm wheel 8 for training the casing in azimuth. The rotor casing 1carries the two reflectors 9 and 10, the lanes of reflection of whichare at right ang es, are normally vertical and intersect in the axis ofthe trans nion 2. The objective 11 and eyepiece 12 are fixed to the casesymmetrically about the centre line of the gym in its central position.and the focal plane and the optical centre of the objective are arrangedso that they are equidistant from the trunnion axis 4.

The observer sits with his back to the target with his eye to theeyepiece 12 and as the ship rolls or pitches the observer and the outercase 5 move with the ship. The image of the target in the focal laneremains steady and in the same relative osition to the cross wires inspite of the rol ing of the ship. The explanation of the steadiness 0fthe image is that when the objective 11 rises and falls the image of thetarget formed bv the objective on the focal plane rises and same amountas the ob'ective since they and the objective are equi istant from theaxis 4. Hence angular motion about axis 4 does not affect the crosswires.

Any angular motion of the casing 5 about the rotor axis in its centralposition causes the objective to rise and the eyepiece to fall (or viceversa) by equal amounts but it simultaneously inclines the'line ofintersection of the two mirrors 9 and 10 and the result is that theimage of the target remains on the cross wire but becomes slightlyinclined to the vertical. An straying motion of the gyro about thevertical trunnion does not affect the position of the image on the crosswire but straying motion about the horizontal trunnion raises or lowersthe image of the target on the cross wire. The gravitational stabilityabout the horizontal trunnion axis 4 is intended to prevent the strayingfrom exceeding a small value. hen the gyro strays about the verticaltrunnion axis 2 it can be brought back to the central position by meansof a torque applied to the end of the trunnion axis 4 which projectsthrough the case 5 and may be furnished with a friction head 4' for thatpurpose. When it strays about the horizontal axis it can be brought backby means of impacts imparted to the rotor casing by turning the fourprong-ed sprocket 13 by means of the knob 15, causing the spokes of thesprocket to engage with the light spring 14 which is attached to therotor casing. These impulses may be applied to the rotor casing by anyother suitable means, electrical or mechanical. The switch for closingthe firing circuit consists of a lever 16 which turns on a fulcrum 17attached to the casing 5 the lever being actuated by a pin 18 attachedto the gimbal ring 3 engaging with a sloton the lever. the lever beingshown in Fig. 1 in its central position with the pin 18 in the slot. Thelever 16 makes contact with one or other of two switch plates 19 and 20.19 being used for firing on the up roll of the ship and 20 for firing onthe down roll, an auxiliary two-way switch serving to throw over fromone to the other. The diagram of connections is shown in Fig. 11. Thefiring key 29 is in series with the twowav switch 2 the battery 28 andthe gyro switch 16 and if the two-way switch is thrown over to pass thecurrent to contact 19. then. if the firing kev be closed at thebeginning of the up roll, the firing circuit is not closed until thelever 16 moves from the switch plate 20 on to the plate 19.

If the rotor axis deviates in azimuth from the central position theimage of the target moves up and down by a small amount relatively tothe cross wire with each roll and if the greatest accuracy of shootingis aimed at, an alternating precession would have to position of theimage on the.

be introduced to compensate for this motion. This compensation is moreaccurately done optically as shown in Figs. 3, 4 and 5. The opticalcompensation consists in mounting the objective 11 and eyepiece 12 on aplate which is pivoted on a pin 22 on the outer casing 5. The samecompensation applies to any tilting of the gyro axis about the trunnion4 and obviates the necessity of introducing a means of precessing thegyro about the horizontal trunnion.

If the gyro axis becomes tilted out of the horizontal plane by rotationabout the trunnion 4, the image of the target is raised, let us say, onthe cross wires. The superposition of the image again on the cross wirescan be brought about by a corresponding lowering of the objective or araising of the eyepiece or a combination" of both. This combination isbrought about by turning the plate 21 on the pin 22. The straying of thegyro must not affect the time of closing of the gyro-switch, hence thecompensating rotation of the switch plate 21 about the pin 22, must alsotilt the switch about the trunnion axis 4 through an angle equal to theangle of tilt of the gyro which has to be compensated. To carry thisinto efi'ect the gyro switch lever 16 instead of being pivoted on thecasing is pivoted on a frame 23 (Figs. 3, 4 and "5) which is mountedpivotally on the trunnion axis 4, the switch plates 19 and 20 being alsocarried by the frame 23. This frame 23 is turned about the axis 4 by theprojecting arm 24 and the connecting rod 25 which connects it with thepin 26 which projects from the plate 21 through a slotted hole in thecasing 5. The length of the arm 24 and eccentricity of the pin 26 are sochosen ,that the tilting of the switch about the trunnion 4 is equal tothe tilting of the gyro about the same axis when the opticalcompensation is complete.

Fig. 6 shows an alternative method of mounting the mirrors on the gimbalring instead of on the gyro case, the mirrors 9 and 10 being attached tothe gimbal ring 3 by the two arms 27. Instead of being fixed to thegimbal ring they might equally well be carried on the horizontaltrunnion 4, the objective and eyepiece being suitably arranged tocorrespond.

An object onable feature of the constructions hereinbefore described isthat the observer has his back towards the target. Figs. 7. 8. 9 and 10illustrate respectively a side elevation. a back elevation with the gyroremoved. a sectional plan and front elevation of an arrangement of partswhich overcomes this objection and which has certa n other advantages.

The rotor casing'l is carried on the vertiealtrunnion 2 in the gimbaring 3 which is supported on the horizontal trunnion 4, at one end ofthe case 5 and at the other scope are rigidly attac end on the U-shapedbracket 30. The outer case is rigidly attached to the bracket oi theelevating telescope of the director sight, b a suitable fixin which isnot shown. 'l he objective 11 an e 'epiece 12 of the teleed to thecylindrical sleeve 31 which can turn on the cylindrical projection 32 ofthe casing 5, suitable apertures being cut in the cylinder 32 to clearthe beam of the telescope. The optical centre of the objective and thefocal plane are equidistant rom the centre of the cylinder but onopposite sides of the centre.

The telescope is of the ordinary type containing four reflectors as inprismatic binoculars. All four reflectors may be attached to thetrunnion axis' 4 but in the arrangement illustrated only two 33 and(Fig. 9) are attached to the trunnion axis 4 by the crank arm 37, theline of intersection of the two planes of reflection being perpendicularto the trunnion axis. The other two reflectors 35 and 36 (Figs. 9 andare carried by the cranked arm 38 which 13 pivotally attached to thecasing 5 by the pin 39. The line of intersection of the planes ofreflection of and 36 is normally coazrial with the trunnion 4. Themotion of the cranked arm 38 about the pin 39 is controlled by a pin 40attached to the arm engaging in a slot in the L shaped lever 41 whichturns on a boss 42 on the easing 5 concentric with the trunnion Thevertical arm of the L sha ed lever is actuated b the screw 43 wor 'ng inthe nut 43, which is attached to the casing 5, pressing against the pin44 which pro ects from the L shaped lever through a slotted hole in thecasing 5. By turning the screw 43 the cranked arm 38 can be raised orlowered about the pin 39 and the two reflectors 35 and 36 are thusraised or lowered. The L shaped lever 41 carries the switch which isshown in Fig. 8. The switch lever 16 which bears on the two switchcontacts 19 and 20 is pivotally mounted on the pin 45 and is connectedby the link 46 with the escapement lever 47,. which is pivotally mountedon the pin 43, and is actuated by the trigger 45' which .is attached tothe gimbal ring 3 by the projecting arm 49. n this way a highmagnification of the motion of the gimbal ring is obtained on the switchlever.

The image of the target can be elevated or depressed in the field ofview by turning the screw 43. The image remains stationary on the crosswires so long as the gyro does not recess about the horizontal trunnion4. en the ship rolls so much that the beam from the target after passingthrough the objective misses the reflectors altogether so that the fieldof view is dark, the image of the target can easily be brought into thefield again by turmng the cylindrical sleeve 31 carrying the objectiveand eyepiece on the cylindrical projection 32 of the casing 5, inopposite phase to the roll so as to keep the line joining the objectiveand eyepiece roughly horizontal. A quick motion once during each roll isequally efiective.

The ratio of the distance of the pin 41) from the trunnion. axis 4 andfrom the pin 39 is so arranged that when optical compensation is appliedby'thc screw 43 to compensate for any precession of the gyro about thetrunnion axis 4. the L shaped lever 41 carrying the switch. is turnedround the trunnion axis 4 through an angle equal to the angle throughwhich the gyro has prccessed.

In the foregoing the gyro has been described with its rotor axishorizontal but it can equally well be employed with its rotor axisvertical, in which case the trunnion axis 2 becomes horizontal and thctrunnion axis 4 remains horizontal as illustrated. The other partsremain as illustrated except the trigger 45 which would be attached tothe side of the gimbal ring in a convenient position to maintain theposition relatively to the switch which is illustrated.

The arrangement of the reflectors illus trated in Fig. 9 is not the onlyone which I may use; for example I may douhlv reflect the beam afterpassing through the objective first in the horizontal plane and next inthe vertical plane but the combination of reflectors with the verticaledge be tween them must necessarily be stabilized by the gyroscope.

Many other optical methods of compensating for the tilting of the gyroabout the horizontal trunnion 4 are practicable. For instance I maystabilize all 4 reflectors bv attaching them to the trunnion axis 4 andcompensate by moving a deflecting prism along the line of collimation ofthe telescope, or by tilting a thick piece of glass interposed in thebeam or by moving the objective relatively to the eyepiece round thetrunnion 4 or by any other suitable optical device. In each case thelinkage with the switch must be such that the motion required tocompensate moves the switch round the trunnion 4 through an angle equalto the tilt of the gyro about axis 4.

The apparatus has been described above in connection with theelimination of the efiects of rolling of a ship but it can equally beapplied to the yaw or motion in azimuth.

The optical system illustrated in Figs. 2. 6 and 9 are not the only onesI may use. In general, I may use any telescope system which gives anupright image. the inverting portion of the system being stabilized bythe gyro and the various dimensions of the system being chosen so thatthe imafle remains stationary on the cross-wires. For example, I mayemploy a system like that illustrated in Figs. 12 and 13. The objectiveand the eyepiece lenses 51 and 52 are attached to the telescope ring asin 'Fig. 9. The prism 53, a side elevationof which is illustrated in F i13, is stabilized by the gyro. The trave ling achromatic prism 54 servesto keep the ob ect on the cross-wires when the gyro-axis tilts, thetranslation of the prism 54 parallel to the axis of the telescope beinglinked up to the switch-plate by suitable mechanical linkage.

Figs. Hand 15 show two elevations of another arrangement I may employ.The objective 55, the eyepiece 56-57 and the rightangled prism 5859 movewith the ship, while the right-angled prism 60 is stabilized by thegyro. In order to compensate for the tilting of the gyro-axis I maytranslate the prisms 58 and 59 and link this translation with theangular motion of the switch-plate by suitable linkage, similar to thatillustrated in Fig. 9. r

Fig. 16 shows an arrangement I may employ which contains no prisms orreflecting surfaces. The objective 61 and the eyepiece 62-62 move withthe ship. The focal plane of 61 is at 63 and the inverting lens orsystem of lenses 64, which is stabilized by the gyro, forms an uprightimage in the second focal plane 65. In order to compensate for thetilting of the gyro-axis I may translate the inverting lens system 64 upand down by the same mechanism which moves the switch-plate. Forexample, I may attach the lens 64 to a crank 66 which normally turnsabout a crank-pin 67 co-axial with the gyro-trunnion. This crank isstabilized by the gyro by means of a pin 68 carried by the gyro-trunnionengaging in a slot 69 in the crank 66. The crank-pin 67 is linked to theswitch-plate by a suitable linkage, for example the pin 67 might beattached to the lever 38 in Fig. 9, and the ratios of the links areadjusted so that when the lens 64 is moved so as to keep the image onthe crosswires the switch-plate is turned through the same angle as thegyro has tilted. Tl'llS arrangement of levers might applied the prism 58in Fig. 12 to move it up and down and thus to obviate the necessity ofusing the prism 54.

In general I arrange-an electric contact mechanism preferably betweenthe outer casing and the gimbal ring. This mechanism may take form of abrush attached to the gimbal ring bearing on a contactattached to theouter casing. I prefer however, to mount both members of the switch onthe outer casing and actuate it by a cam or trigger gear attached tothegimbal ring. The velocit ratio of the cam'or trigger gear is arrangeso that it has its maximum value at the instant when contact is mad Inorder to keep the contact in a constant 1, ,eoe

position relatively to the horizontal plane, I

may arrange the whole telescope, preferably of the prismatic type, to-bemounted on the rotor caslng, but it is evident that while the ship isrolling and the observer is looking through the eye piece of atelescope,

which is maintaining a constant direction in space, he could not fail toapply forces to the eyepiece and thereby alter the setting of thetelescope. y

I overcome this difliculty in one or other of two ways. I may leave allparts of the telescope connected to the rotor casing except theeyepiece, which I attach to the outer casing and I arrange the parts sothat the centre of the focal plane of the telescope is virtual] theintersection of the gimbal axes. e observer is then looking through aneyepiece which moves with the ship at an image of the horizon whichappears stationary in the field of view.

An alternative method which I may adopt is to fix both the objective andthe eyepiece of the telescope to the outer casing and fix only themirrors of the telescope to the rotor casing. For example, I may fix theobjective and the eyepiece side by side on the outer casing so that theobserver stands with his back to the target, and I fix to the rotorcasing two mirrors say at degrees to each other, and making normally 45de es with the line of collimation, the line 0 intersection of the twomirrors coinciding with the vertical gimbal axis. The eyepiece may beplaced at any suitable angle or position by further reflectors attachedto the outer casing. The observer on looking through, the telescope,sees the horizon stationa on the cross-wires irrespective of the ampitude of the motion of the ship. If the ship is simultaneouslypitchingand rolling when the tele scope is trained on the beam, the horizonappears to tilt relatively to the horizontal wire, through an angleequal to the angle. of pitching, but as this tilting takes place aboutthe axis of collimation, it does not mislead the observer if he watchesthe point of intersection of the horizon with the horizontal wire andkeeps it in the centre of the field.

In order to produce the required precession of the gyroscope about thegimbal axis, I arrange two little cranks or handles on the outer casing,the turning of which turn two light flails of spring steel, which beingcaught by stops in their revolution are later released and impartstandard impacts to the f rotor casing. Or, I ma employ the mutualattraction or repulsion tween two coils or between coils and magnets,one coil of each pair being fixed to the gimbal ring and the other tothe rotor casing, the coils being energized by currents controlled byswitches outside the outer casing. Or, I may employ simple bell crankmechanisms actuating flexible levers inside the outer casing which arebrought to bear on the rotor casing or on the gimbal ring. I preferablyarrange the handle of the bell-crank mechanism so that theprecessiontakes place in p the direction of the motion of the handle.

In order to deal with the yawing motion of the ship I may fit anotherswitch to the same gyroscope, between the rotor casing and the gimbalring so as to be operated by the motion of the roscope about thevertical gimbal axis. at I preferably employ two gyroscopic sightingtelescopes and two observers, one of whom has to keep his horizontalcross wire on the horizon near the target ship and the other has to keephis vertical cross wire on the target ship. The whole apparatus maysimply be duplicated the horizontal trunnion axis in the one instrumentbeing turned into the vertical direction in the other.

I arrange the angle of contact in the switch which controls the yawingto be greater than that in the switch which controls the rolling motion,and by means of a relay I may arrange so that the gun will not fireunless the yawing contact is already made when the rolling contact isfirst made. I. may interconnect the two relays so that should therolling contact be made before the yawing contact the yawing relaybecomes locked and cannot be closed.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is 1. In fire-control ap aratus for a gun mounted on anangularl y moving platform, the combination of a gyroscope, a switchadapted to be controlled thereby, and means associated with the switchfor correcting for the effect of straying of the gyroscope thereon.

2. In fire-control apparatus for a gun mounted on an angularly movingplatform, the combination of a roscope, a switch adapted to be controled thereby, optical means for detecting straying of the gyroscope, andmeans associated with the switch for correcting for the effect of suchdeviation.

3. In firecontrol apparatus for a gun mounted on an angularly movingplatform, the combination of a gyrosco e, a switch adapted to becontrolled there v and comprising a movable contact and a fixed contact,a member movably mounted with re spect to the roscope and carrying thefixed contact, an means for moving the member to change the relationbetween the movable contact and the fixed contact in accordance withdeviations of the gyroscope.

4. In fire-control apparatus for a gun mounted on an angularly movingplatform, the combination of a gyroscopc an optical sighting systemhaving some of its elements mounted on the gyroscope, means whereby theother elements may be moved to compensate for movement of the firstnamed elcments caused by deviation of the gyroscope, a firing switchadapted to be controlled by the gyroscope and means operativelyconnected' to the first named means for correcting for the effect ofsuch deviation upon the time of firing of the gun.

5. In fire-control apparatus for a gun mounted on an angularly movingplatform. the combination of a gyroscope. an optical sighting systemhaving some of its elements mounted on the gyroscope, means whereby theother elements may be moved to compensate for movement of the firstnamed elements-caused by deviation of the gyroscope, a switch forcontrolling the firing circuit and having a contact operativelyconnected to the gyroscope. a member movably mounted with respect to thegyroscope and carrying a switch contact adapted to cooperate with themovable contact. and means connecting the member to the means for movingthe elements of the optical system, whereby the relation between thecontacts may be changed to compensate for the effect of deviation of thegyroscope upon the time of firing of the gun.

6. In fire-control apparatus for a gun mounted on an angularly movingplatform, the combination of a gyroscope, an outer casing therefor. anoptical sighting system having some of its elements mounted on thegyroscope, a member movably mounted on the casing and carrying otheroptical parts, a switch for controlling the firing circuit comprising acontact adapted to be moved by relative movement between the gyroscopeand the casing, a member movably mounted with respect to the gyroscope,a switch contact carried on the member and cooperating with the firstnamed contact, and connections between the last named member and themember which carries the other op tical parts whereby the said parts andthe switch contact may be simultaneously moved to compensate for theeffect of straying of the gyroscope thereon.

7. In fire-control apparatus for a gun mounted on an angularly movingplatform, the combination of a gyroscope, a switch adapted to becontrolled thereby, an optical sighting system associated with thegyroscope. and means operatively related to the switch and the sightingsystem for compensating for the effect of deviations of the gyroscope onthe same.

, 8. In fire-control apparatus for a gun mounted on an angularly-movingplatform, the combination of a gyroscope, an outer casing therefor, aswitch ,for controlling the firing circuit including a contact adaptedto be moved by relative movement between the gyroscope and the casing,a. frame movably mounted with respect to the gyroscope, a switch contactcarried on the frame and cooperating with the first named contact, andmeans for moving the frame to compensate for the effect of straying ofthe gyroscope upon the relation between the contacts of the switch. v

9. In fire-control apparatus for a gun mounted on an angularly movingplatform, the combination of a gyroscope, an outer casing therefor, aswitch for controlling the firing circuit including a contact adapted tobe moved by relative movement between the gyrosco and the casing, aframe pivotally mounte upon one of the supporting axes of the gyroscope,a switch contact carried on the frame, and means for swinging the framein accordance with straying of the gyroscope to compensate for theeffect of such straying upon the contacts of the switch.

10. In a directon firing system for a gun mounted on an angularly movingplatform, the combination of a switch for controlling the firingcircuit, gyroscopic means for stabilizing the action of the switch, and

means for adjusting the switch to compensate for stra ing of thegyroscopic means.

11. In a director firing system for a gun mounted on an angularly movingplatform, the combination of a switch for controlling the firingcircuit, optical sighting means, gyromopic means for stabilizing theaction of the switch and the sighting means, and means for adjusting theswitch and the sighting means to compensate for straying of thegyroscope means.

JAMES ILACKLOCK HENDERSON.

